Automatic closing device for sliding doors.



L.- A. ABBOTT.

AUTOMATIC CLOSING DEVICE FOR S LlDlNG DOORS. APPLICATION F|LEDAUG-19,1912.

1,16,755, Patented Feb 1, 1916.

2 SHEETS-SHEET I.

THE COLUMBIA PLANOORAPH CO WASHINGTON, D--( L. A. ABBOTT.

AUTOMATIC CLOSING DEVICE FOR SLIDING DOORS.

APPLICATION man AUG. 19, m2.

1 169355. Patented Feb. 1, 1916.

' 2 SHEETS-SHEET 2.

AUTOMAT C cnosrive-nnvrcn FOR SLIDING noons.

I To all whom it may concern Be it known that I, LAwnENcn A. ABBOTT, acitizen of the United States, and a resident of the city of Chicago, inthe county of Cook and State of Illinois, have in vented certain. newand useful Improvements in Automatic Closing Devices for Sliding Doors;and I do hereby declare that the following is a full, clear, and exactdescription of thesame, reference being had to the accompanyingdrawings, and to the numbers of reference markedthereon, which form apart of this specification. 7

Thisinvention is adapted for use for insuring the closure of ha-tchwayor elevator doors or sliding doors of any kind.

Although it is the usual; requirement of the underwriters in the variouscities, that hatchway doors should be fully closed before the elevatorleaves the floor, to which the door opens, in practice, the operator, ifhe attempts to close the door'at all, usually starts the closingmovement at about the same time that he starts the cage or plat form. Inconsequence, where such doors are closed manually, it frequently occursthat the door is not wholly closed, leaving the hatchway unguarded andinviting accident.

Although automatically closing devices have been introduced to someextent, such devices, as a rule, close the doors with considerableviolence, usually the velocity of the door in closing, increasing as, itapproaches a fully closed position, so that should a person attemptingto leave or enter the car be struck or caught between the door sections,he would be likely to be firmly held and almost certainly severelyinjured.

The object of this invention is to afford an automatic closing devicefor sliding doors so constructed and installed that the door afford aconstruction in which energy is stored in a spring during the opening ofthe door, said spring acting torsionally to 1m? Specification of LettersPaten't.

Patented net; L am.

p ueatioafiieanugu t '19, ieia s ri nd. 715,760. l

pe'l' the. doors to closed position'when released and to produce quick,though gentle, closure.

The invention embraces many novel fea-' tures and consists in thematters hereinafter described and more fully pointed out and defined inthe appended claims.

In the drawings: Figure 1 is a fragmentary front elevation, showing twooppositely slidable doors equipped with automatic closing meansembodying my invention. Fig. 2 is an enlarged fragmentary view showingone of the doors with the closing means therefor broken away. F ig;

3 is an enlarged section taken on line 3-3 of Fig. 2, with the dooromitted. Fig. 4 is an enlarged section on line 4l of Fig. 2. Fig. 5 isan enlargedsectional detail of one of the outer or end bearings for thespiral shaft. Fig. 6 is an enlarged fragmentary sectional view'of thecenterbearing for the actuating shaft.

As shown in thedrawings: 1,'indicates a wall having an openingtherethrough, at which isslidably supported a door comprising sections 2and 3, adapted to close said opening and operated to closeautomatically.

As shown, ways or guides for said door are secured horizontally on thewall above the same. For this purpose, if preferred, a fiat plate or bara, may be rigidly secured to the wall by riveting or bolting, and secured thereto are upper and lower ways 5 and 6,;whichextend horizontallyabove and on each side the door at equal distances apart, and for alength sufiicient to permit the requiredtravel of the door sections tofull opening. Said guide bars 5 and 6, are concaved in their adjacentedges, as shown in Fig. 3,, andslidably engaged therebetween onanti-friction balls 7, are the sliding bars 8, one for each door, andthe doors gage in the sliding bar. V

Secured onthe plate 4, above the way5,

and above the middle of each door, is a bracket 11, in which isjournaled a shaft 12, having an integral peripheral collar near each endthereof, which is grooved .on the outer side to receive therein balls13, which operate in a groove in the face of the bracket, as shown 1nFig. 6, to afl'ord'a ball bearing for said shaft at each end.

Rigidly connected at each end of said I shaft are oppositely directedright and left vexed bearing faceon the screw shaft.

' with the projection, is provided with a seat 20, in which'is containeda ball 21. which bears against a plate 22. and anadjustinp; screw 93.extends a'xiallv throueh the head of'said bearing" and carries a plate21, which bears agai st said ball to take the thrust at all times of thescrew'shaft.

Secured on each of the sliding bars 8, above the midd e of each door. isa bracket 25," having rollers '26 and 27, journaled therein, one aboveanother, the axes of which are paral el and on opp site sides of thescrew s aft, as shown in Fig. 3. As shown, said rollers are reduced slihtlv in circumferenceat the ends to afford a slightly con- A strongspiral spring 28. is secured at one end on the collar 12, on the shaft12. and is wound about said shaft 12. and at the other end enaa es inthe back plate 4,'as

' sh wn in Figs. 1 and 2.

"Atth'e moment the'door is released..how-

The operationisas follows: The spring; is set at. neutral or to exertvery slight torsi nal'stress when the doors are closed.

, lV en eit er do r is im elled to open position by sliding the samelaterally. such lateral mo ement rotates the shaft bv the eneaseme t ofthe rollers on said spiral shafts 14 and'15. and both'doors m veoutwardly and oppositely, and may be held in open nosition by anysuitable means or manually.

ever. fr m open po ition. thetorsion of the spring 28. reverses therotati n of the shaft,-

whereby the doors areimpelled inwardly toward clo ed. position, t espeed of such movement be inning to decrease when the do rs are nearlyclosed. and decreasing until fully clo ed. owi g to the decreasingtorsicnal action of the surina'.

Wh che er door is actuated in opening, the ball ro er bearings receiveall the thrust thereof. The constr ction is suchas to permit, the d orsto yield verv readily in openine and in winding up the spring, whichreed not'be of great strength owing to the fact that the shafts arejournaled upon ball patent issued on this application for patentotherwise than necessitated by the prior art.

I claimas my invention:

1. In a device of the class described a pair of oppositely disposedright and left handed thread worm shafts, an intermediate member rigidlyconnected to the adjacent ends of said worm shafts, bearings supportingsaid intermediate member and worm shafts, integral flanges on saidintermediate member affording together with said bearing a ball race fora thrust bearing, and a spring wound about said intermediate member andattached thereto andto a fixed support to resist rotation of saidintermediate member and worm shafts.

2. In a device of the class described a pair of right and left handedthreaded worm shafts, an intermediate member rigidly connected to each,grooved flanqes integrally formed on said. intermediate member, groovedsupporting brackets for said member and cooperating; with said flangest0 afford a thrust ball bearin therefor, a spring wound around saidmember and connected to one'of said flanges and to a fixed support toresist rotation of said member, and roller ball-bearing mechanismengaging said worm shafts adapted to progress therealong with rotationof said shafts.

3. In a device of the class described a plurality of worm shaftsarranged in axial alinement. a spring, controlled intermediate memberrigidly connected to each of said shafts to resist movement thereof in acertain direction. door supportina brackets onagino aroundsaid wormshafts. and rollers journaled in said brackets adapted to contactopposite faces of said worm shafts to cause progression of saidbrackctslonoitudinally of said worm shafts with rotation of said shafts.

4. In a device of the class described grooved brackets rigidly securedupon a wall, a shaft iournaled in said brackets havingan integralperipheral grooved collar near each end thereof. ball bearings, saidbrackets and said collars arranged to all'ord a race for said ballbearin s. a worm shaft rigidlv connected at each end of said shaft in axal alinement therewith. an integral pro ection on the outer end of saidworm shafts. a spacin member thereon. a pair of apertured bracketsrigidly secured on said wall. r llers therein adapted to receive saidprojecti ns journaled therchetwecn. adjustable ball bearing meansmounted in said. apertured brackets to take the thrust of said wormshafts, roller door supporting memhers movably engaged with said worm Intestimony whereof I have hereunto shafts, and a spring Wound around saidfirst subscribed my name in the presence of two 10 mentioned shafthaving one end thereof se subscribing Witnesses.

cured in one of said grooved collars and the T 4 1 other end thereofrigidly fastened to the LAWRELCD ABBOTT wall, said spring acting toautomatically Witnesses: close the doors when the same have beenLAWRENCE REIBSTEIN, opened. SHELEY R. MEYER.

Copies. of this patent maj be obtained for five cents each, byaddressing the Commissioner of Patents, Washington, D. C.

